Chromatography Forum

Two months ago a T cylinder of UHP He was $375. It just jumped to $830 for my latest cylinder. Another supplier can't get He at all for at least a couple months.

This is really motivating me to switch to hydrogen.

LALman wrote:
Two months ago a T cylinder of UHP He was $375. It just jumped to $830 for my latest cylinder. Another supplier can't get He at all for at least a couple months.

This is really motivating me to switch to hydrogen.

I thought it was really expensive compared to our cost, until I looked up the T cylinder, which is almost 10x larger than our standard cylinders. Ours are running a little less than $200, which is almost twice the new price for the T cylinders.

We are still looking in to switching to hydrogen and already have switched everything but the GCMS units. 8260/624 is almost impossible until some allowances are made from EPA. 8270/625 I can make work, but a few analytes have much worse performance.

Ouch-I'm going to call and order one or even two tomorrow if the price hasn't gone up.

Interestingly enough, I had a long meeting last week with some representatives from Airgas(we currently use a local supplier), although most of our helium discussion was about liquid. We normally get that from Praxair, and were allocated down to 60L from our standard 100L(a couple of times a year). Airgas is claiming that they're at 100% allocation for existing customers, although they were running at 60% earlier this year also.

I've done some testing with our GCs on hydrogen and have shown that we can do everything we do now with higher throughput, but I'm getting push back from faculty on switching. The GC-MSs can be done with little consequence other than the fact that with our current plumbing arrangement, an "all or nothing" approach is easier with both the GCs and GC-MSs in the loop.

I've been running hydrogen for my GC-FID DRO machine. It works great there. But I have to kick off with a blank to begin. It seems that after a run finishes and then sits with hydrogen flow the rest of the night; that puts enough contaminants on the column that the first run will show a heavy spiked pattern that looks like DRO shifted to later RT and about 60 ppm (my MDL is 25ppm but more typically <10 ppm). All the plumbing is RESTEK cleaned SS 1/8 tubing. So I figure the hydrogen is leaching it from somewhere in the system or maybe its in the hydrogen and sticking to the column. At idle it is flowing 5 mL/min and 60C.

I was doing pretty well running hydrogen in my GC-MS in a clean machine. I installed a SS T-valve so I can switch between hydrogen or helium with just a valve turn; as James_Ball suggested in another post. It sure cleans up my source to leave it running over a weekend. But I must now have active sites somewhere because the easily degraded halogens are just terrible when I tried running a few with hydrogen. I had perhaps 25-50% less area on half a dozen compounds before. But at present its near total loss.

Helium really covers over many sins.

I had another lab call me to ask where I bought my helium because the local Airgas vendor told them no availability for at least 2 months.

I went through the helium availability issue here about a year ago. Our higher ups in the municipality got a contract with a company that claimed "same quality, cheaper prices for all gases" without checking with those of us that use it, and I got stuck with a lower grade of helium. When I looked into getting a higher quality from the company, they quoted $830 compared to $230/tank, and they only have the 2 grades available. I tried to get gas from our last supplier, and they told me that they weren't taking new He contracts. None of the local suppliers were taking "new" clients.

I switched to nitrogen for the purge & traps to reduce my usage, and was seriously considering changing to hydrogen for carrier gas until last week. I had an annual PM from Agilent on my 7890B GC/5977B MSD/ATOMX XYZ, and the service tech advised against it. He said they are finding that hydrogen is damaging/affecting the magnets in the MSD's over time, among other things. I had only heard good things about hydrogen (once you get up and running) up to this point. I am going to hold off for now, until I find out more about this.

Has anyone heard/experienced anything similar? I have noticed that Agilent hasn't been pushing the switch to hydrogen as much as they used to, when I first started working on a GC/MS system at work (Municipal drinking water/waste water lab in Ontario, Canada).

Just curious

James:
We are still looking in to switching to hydrogen and already have switched everything but the GCMS units. 8260/624 is almost impossible until some allowances are made from EPA.

What is the main problem with 8260? Tuning or reactivity? The tune criteria were adjusted in 8260D to allow hydrogen but there wasn't much input on problems labs were facing.
Reactivity is another can of worms all together.

I also, am using nitrogen from a dewar as my purge gas and general use gas.

Steve Reimer wrote:
James:
We are still looking in to switching to hydrogen and already have switched everything but the GCMS units. 8260/624 is almost impossible until some allowances are made from EPA.

What is the main problem with 8260? Tuning or reactivity? The tune criteria were adjusted in 8260D to allow hydrogen but there wasn't much input on problems labs were facing.
Reactivity is another can of worms all together.

Its the 96 mass in BFB that gets too large at the expense of mass 95 which becomes proportionally lower and that affects the 174/95 ratio. I assume the hydrogen is adding a proton to the 95 mass. The other losses were as I said for brominated and chlorinated compounds about 25% of the signal area you would get with helium. It helped me to purge with argon or nitrogen and then dry purge with helium for 1 minute before desorption. In my experience hydrogen reacts more with the 8260 analytes under argon or nitrogen but less so with helium; that helped the recoveries of halogenated compounds.

LALman wrote:
I also, am using nitrogen from a dewar as my purge gas and general use gas.

Steve Reimer wrote:
James:
We are still looking in to switching to hydrogen and already have switched everything but the GCMS units. 8260/624 is almost impossible until some allowances are made from EPA.

What is the main problem with 8260? Tuning or reactivity? The tune criteria were adjusted in 8260D to allow hydrogen but there wasn't much input on problems labs were facing.
Reactivity is another can of worms all together.

Its the 96 mass in BFB that gets too large at the expense of mass 95 which becomes proportionally lower and that affects the 174/95 ratio. I assume the hydrogen is adding a proton to the 95 mass. The other losses were as I said for brominated and chlorinated compounds about 25% of the signal area you would get with helium. It helped me to purge with argon or nitrogen and then dry purge with helium for 1 minute before desorption. In my experience hydrogen reacts more with the 8260 analytes under argon or nitrogen but less so with helium; that helped the recoveries of halogenated compounds.

This was the main problem for us also. If we could switch to 8260D it would be great but we do as many or more 624.1 samples and 524.2 and 524.3. I didn't lose that much 95 to affect the 174 ratio, but could almost never get the 96 down low enough. The longer I ran hydrogen the better it got, but I went from 96 being almost 85% versus 95 down to about 20% which was still too high for most methods. Someone from Tekmar said they made it pass with a flow rate of 0.3ml/min carrier, but that is barely 2 psi even with a 30mx0.18 column, very difficult to maintain at a steady flow.

Also as above I have seen problems with active compounds in 8270/625, but I think if I can burn out all the hydrocarbon background the hydrogen releases from the flow path I might get some of them back. I am also looking to see if solvent evaporation using the MultiMode injection port in solvent vent mode will help. Maybe inject cold then flash onto the column will cause less breakdown. I have used this LVI type injection with even 1ul injections for other tests and it works well, just haven't tried it with hydrogen carrier yet.

We are also working to switch to nitrogen purge for volatiles but have to plumb in the nitrogen, I don't know why when we designed the lab we put everything but nitrogen on the benches in the volatiles room.

I finally got around to calling today.

We're at $205, which is up from $175 earlier this year on a "300" sized cylinder. Still, the price increase was moderate enough that I went ahead and ordered 3.

Now to get more chains and clamps rigged before they come tomorrow...

benhutcherson wrote:
I finally got around to calling today.

We're at $205, which is up from $175 earlier this year on a "300" sized cylinder. Still, the price increase was moderate enough that I went ahead and ordered 3.

Now to get more chains and clamps rigged before they come tomorrow...

I am glad we are down to about 1.5 cylinders per week (I think 1A 9" diameter). I remember when it was 3-4 per week before switching the GC/ECD and FID to hydrogen.

Our contract price just went from $130 to $220 for a 300 cf cylinder.

My pointy-haired boss began hoarding helium cylinders a few years ago because he was afraid of scarcities. Then a few years later the company relocated the lab to another state. Wonder what he did with those cylinders......

benhutcherson wrote:
I finally got around to calling today.

We're at $205, which is up from $175 earlier this year on a "300" sized cylinder. Still, the price increase was moderate enough that I went ahead and ordered 3.

Now to get more chains and clamps rigged before they come tomorrow...

I was at $265 most of last year. I assume a "300" cylinder is 291CF which is what my "T" cylinder holds. Maybe I need to check around for another supplier. And this is for UHP 5? 99.999%?

I just checked our last order versus one from back in the spring and the price is up about 25% for us.

Oddly recently we have had more trouble getting UHP Nitrogen cylinders than Helium. The supplier has to search around at several different locations to find us the 4 we needed a couple weeks ago.